Mar-Vell hasn't been Captain Marvel in decades, in fact he's been dead, so calling him the "real" Capt. Marvel is inaccurate. I really do dislike when fans call a particular version the "real" one when what they actually mean is "my favorite" one. They're have been like three Capt. Marvels since he died.

That's not the point. Carol has been Ms Marvel. Mar-Vell was the first Captain Marvel. So yeah, there is a bias. He is the archetype of "Captain Marvel", to me, and to many others, when it comes to Marvel comics, Mar-vell is Captain Marvel. The Kree. Who has had beef with Thanos, and involved with the avengers..etc so yes, seeing Carol, who was first Ms Marvel would not feel right. The fact that the there have been three isn't the point. Mar-vell was the first, and arguable the "best"